Athene

for iPhone, iPad and Android

Privacy Policy

Athene for iPhone, iPad and Android · Effective 26 October 2026

The short version. Athene has no user accounts and no server of its own. It collects no personal information, and contains no analytics, no crash reporting, no advertising identifier and no third-party code that collects anything. Your books, your reading position, your highlights and your notes stay on your device — and, only if you turn on iCloud Sync, in your own private iCloud. Athene contacts other computers only when you ask it to: a calibre or OPDS library you add, a KOReader sync server you set up, your Zotero library if you connect it, your own model server or an AI provider you supply a key for, Apple’s translation when you translate a passage, and the few public services named below for free books, fonts and the Listen voice.

On Android. Athene for Android has no iCloud Sync, so what this policy says about it applies to iPhone and iPad only. Everything else works as described here, and where the Android app works differently, this policy says so.

Who is responsible

Athene is made by Aditya Sreedhar, an independent developer. This policy covers the Athene app for iOS, iPadOS and Android, and this website. Questions go to athene@theadipost.com.

What Athene stores, and where

Everything below is kept in Athene’s own storage on your device. None of it is transmitted to the developer, because there is no developer-operated server to transmit it to.

Your books. The files you add, the books Athene makes from other formats, and the covers, chapter text and layout caches made from them.
Your reading. Which book is open, your position in it, bookmarks, highlights, notes, the drawings in your notes and on your PDFs, your reflections, and the descriptions Listen has made of the pictures in your PDFs.
Your settings. Typeface, type size, margins, page-turn style, paper and reading theme, library arrangement and collections, and any papers you make and Google fonts you add.
The Listen voice, if you download it.
Server details you enter. The addresses and usernames for your calibre server, your KOReader sync server, any OPDS catalogs and a WebDAV server you use with Zotero, your Zotero username, and the address of an Ollama server if you configure one, are kept in the app’s own settings storage inside its sandboxed container. Secrets are not. Your calibre, KOReader sync, WebDAV and catalog passwords, your Zotero key and, if you supply one, the Owl’s provider key are held in the iOS Keychain, marked to this device only, never in an iCloud Keychain and never in an unencrypted backup. Each is sent only to the server it belongs to. On Android, passwords and keys, your calibre password and your KOReader sync key among them, are encrypted with a key held in the Android Keystore, which never leaves your device, and they are left out of backups and out of transfers to a new phone.

Deleting the app removes all of it from your device. If you have turned on iCloud Sync, the copy in your iCloud stays until you delete it there (see iCloud Sync, below). On Android, uninstalling may offer to keep Athene’s data on the device, so that reinstalling finds your library again; if you keep it, it stays on the device until you reinstall Athene or remove it.

Backups on Android

Android’s backup to your Google Account keeps Athene’s settings and the papers you made. The settings include the addresses and usernames of your calibre server and the catalogs you added, and your Send to calibre choices, but never passwords or keys. The backup doesn’t keep your books, notes, highlights or places in your books. Android encrypts it end to end with your screen lock when you have one, and the developer never receives it. When you move to a new phone with Android’s own transfer, your whole library comes along, books and notes included, but your passwords and keys do not, and Athene asks for them again.

What leaves your device

Athene makes network connections only when you ask it to, in the situations below.

You connect to a calibre library: Your username and password for that server, and ordinary requests to browse and download books, go to the calibre or calibre-web server whose address you typed in. If you turn on Send to calibre, your highlights (with the words highlighted and your notes), how far through each book you are, and whether you have finished it go to that same server, and Athene reads back the highlights calibre keeps for the books you open, including ones you made in calibre’s own reader. Athene talks to it directly; nothing is relayed through the developer or any third party. On Android, Send to calibre is off until you turn it on in Settings › Sync › Calibre, and it sends only to the calibre content server you connected; calibre-web has nowhere to keep highlights, so nothing is sent there. Your calibre password goes only to that server, and never over plain HTTP to a server beyond your home network or your own VPN.
You sync with KOReader: If you turn on KOReader in Settings, Athene connects to the sync server whose address you entered, a server you run yourself, such as the Athene sync server on your own computer, with the account you made on it. To it go the books you choose to send to your e-reader and, for books Athene and KOReader both have, your place in them and your highlights, notes and bookmarks, each with your device’s name, such as “Athene (iPhone)” or, on Android, “Athene (Pixel 9)”, and a random number that tells your devices apart. Athene reads back what KOReader on your e-reader has put there. Athene talks to that server directly; nothing is relayed through the developer or any third party. If you never turn KOReader on, this connection is never made.
You connect Zotero: On iPhone and iPad, if you sign in to Zotero, you do it on zotero.org itself, in Apple’s sign-in window, so Athene never sees your password. zotero.org gives Athene a key to your library, which you can take back on zotero.org at any time; or you can paste a key you made there yourself. With it, Athene reads your libraries and groups so you can browse them, downloads the papers you choose, and asks Zotero for a reference when you tap Cite. For the papers you download, your highlights and notes, with the words highlighted, go to your Zotero library as Zotero annotations a few seconds after you make or change them, and Athene reads back the ones made in Zotero when you open the paper and when you come back to Athene. If you keep your files on your own WebDAV server, Athene downloads them from it with the details you entered and never writes anything there. Athene talks to zotero.org and your WebDAV server directly; nothing is relayed through the developer or any third party. What Zotero does with your library is covered by zotero.org’s own privacy policy. Sign out in Settings › Zotero and Athene forgets the key, and takes it back on zotero.org if it was the one made when you signed in; the papers you downloaded stay on your shelf. If you never connect Zotero, these connections are never made.
You add an OPDS catalog: Requests to browse and download go to the catalog whose address you typed in, and to any other server it links to for a cover or a book. The username and password, if the catalog needs them, go to that catalog and nowhere else: a catalog that links to another server does not get your password sent there.
You look for free books: Open Shelf, and the month’s special in Add Books when Monthly Specials is on, search and download from Project Gutenberg (gutenberg.org). Gutenberg receives what you search for and which books you download, as any website would.
You bring in a book from a link: Athene downloads the file at the address you enter. A share link from Google Drive, Dropbox or OneDrive is turned into that service’s download address, and the request goes to that service.
You send books from a computer: While the From a Computer screen is open, Athene runs a small web server on your device, reachable only from your own Wi‑Fi or wired network at an address that includes a one-time code, and never over mobile data. Files you send from your computer’s browser come straight into your library. It stops the moment you close the screen. On Android, while the screen is open, Athene also announces it on your network under the name “Athene”, so a computer there can find it.
You open Book Stores: In the United States, Add Books lists some stores that sell books without DRM, and two free libraries. Each opens in Safari, where what you do is between you and that store, under its privacy policy; Athene sees none of it. A book you buy reaches Athene only when you open it in Athene. To know whether to show Book Stores, Athene asks the App Store, through Apple’s StoreKit, which country your App Store account is in.
You open Book Stores on Android: In the United States, Add Books lists the same stores and libraries. Each opens in your browser, as a tab over Athene, where what you do is between you and that store, under its privacy policy; Athene sees none of it. A book you buy reaches Athene only when you open it in Athene. To know whether to show Book Stores, Athene asks the Google Play app on your device, through Google’s Play Billing Library, which country your Play account is in, and shows them only when Play says the United States. Nothing is bought or sold through it.
You look for or add a Google font: The list of Google fonts comes with the app. While you browse it, Athene fetches each font’s name, set in that font, from Google Fonts (fonts.googleapis.com and fonts.gstatic.com), and the font itself when you preview or add it, as any website using Google Fonts does. Google receives your device’s network address and the names of the fonts, under Google’s privacy policy. If iCloud Sync is on, your other iPhones and iPads fetch the fonts you added from Google themselves.
You translate a passage: When you choose Translate on a selection, Athene hands the text to Apple’s own translation panel. With the Translate app’s On-Device Mode on, Apple translates it on your device; otherwise the text goes to Apple’s translation service, under Apple’s privacy policy. Athene keeps nothing of it.
You translate words on Android: Translate, in the menu over words you select, uses your phone’s own on-device translation, the service Live Translate uses on a Pixel. Athene hands it the words and sends nothing itself. The languages are downloaded by Android, from its own translation settings, not by Athene. On a phone without that service, Translate isn’t offered.
You download the Listen voice: The first time you use Listen, Athene offers a one-time download of about 242 MB on iPhone and iPad, or about 340 MB on Android, the voice files as their makers publish them on Hugging Face (huggingface.co). Hugging Face receives the request, as any website would. After that, reading aloud happens entirely on your device: neither the text nor the audio leaves it. On Android, the download carries on if you leave Athene, picks up where it stopped, and checks each file before it is used, and Athene keeps the voice out of Android’s backups. While a book is read aloud, Android shows its title, chapter and cover on the lock screen and in the notifications, as it does for music.
You ask the Owl a question, having configured an Ollama server: Your question and the passage of the book you asked about go to the Ollama server whose address you typed in, normally a machine on your own network. Athene talks to that server directly; nothing is relayed through the developer. If you have not chosen this setting, this connection is never made.
You ask the Owl a question, having supplied your own API key: Your question and the passage of the book you asked about go to the provider you picked (Anthropic, OpenAI or OpenRouter), together with your API key so that provider can identify the request as yours. Athene sends this straight to the provider; nothing is relayed through the developer, who never sees your question, your books or your key. What the provider does with it afterwards, including how long it is kept, is governed by that provider’s own privacy policy and the terms of the account your key belongs to. Your key is stored in the iOS Keychain on your device and is sent nowhere else. Asking the Owl about a word from the dictionary works the same way, under the same setting. On Android you can also type in the address of another server that works like OpenAI’s, and your question, the passage and your key go to that server instead; there, your key is kept encrypted with the Android Keystore, as described above.

Athene makes no other connections. It does not phone home on launch, does not check for updates, and does not fetch remote configuration or advertisements. On Android, Athene also asks Google Play for your Play country when you open Add Books, as described under Book Stores.

Everything Athene sends to a public service goes over an encrypted connection (HTTPS). A server on your own network, such as an Ollama, calibre or KOReader sync server, often uses plain HTTP; then what Athene sends to it crosses your network unencrypted, unless it goes through an encrypted VPN such as Tailscale. To a server on the internet that isn’t encrypted, Athene connects only once you have agreed to it.

iCloud Sync

iCloud Sync is on iPhone and iPad only, and is off until you turn it on in Settings. When it is on, Athene keeps a copy of your reading in your own private iCloud database, through Apple’s CloudKit, so that your other devices signed in to the same iCloud account can have it: where you are in each book, your bookmarks, highlights, notes and drawings, your collections, the papers you made, the Google fonts you added, and your reading settings. The books themselves are not uploaded; each device keeps its own copy, and Athene recognises the same book on two devices by a fingerprint worked out from its text.

The developer cannot read any of it: it is in your iCloud account, not on any server of the developer’s. Book titles and authors, the words you highlighted, your notes and drawings, and the names of your papers and collections are stored in CloudKit’s encrypted fields, which are encrypted on your device with keys kept in your iCloud Keychain. The rest is stored as ordinary iCloud fields: positions and bookmarks, where each highlight sits and its colour, dates, your reading settings, the colours of the papers you made, the names of the Google fonts you added, the book fingerprints, and, for each device, a random identifier and whether it is an iPhone or an iPad. Apple may wake Athene briefly in the background to deliver changes from your other devices. Apple’s handling of iCloud data is covered by Apple’s privacy policy.

Turning iCloud Sync off stops syncing and leaves the copy in iCloud as it was. To delete that copy, open Settings on your iPhone or iPad, tap your name, then iCloud › Manage Account Storage, choose Athene, and delete its data. That removes it from iCloud and leaves your device untouched.

The Owl, Apple Intelligence and Gemini Nano

When the Owl uses Apple Intelligence, which is how it is set up until you change it, the text of your question and the passage it is about stay on your device and are not transmitted anywhere. Apple’s on-device foundation models are covered by Apple’s own privacy terms. The short summaries on calibre book pages are written on your device. On Android, when the Owl answers from your own Ollama server or an AI provider instead, a calibre book’s page offers Ask the Owl: only when you tap it, and only if you have already agreed to send questions there, the first few pages of that book, with its title and author, go to that server or provider, as a question would.

On an Android phone or tablet that has Gemini Nano, the Owl uses it first. Athene reaches Gemini Nano through Google’s ML Kit, and Android’s AICore service runs it on your device: the text of your question and the passage it is about stay on your device and are not transmitted anywhere. ML Kit would otherwise send Google statistics about its own use, such as the device model, the app’s name and version, an identifier for this installation, and how long requests took; Athene turns that reporting off, so nothing is sent. If Gemini Nano isn’t on your device yet, tapping Download asks Android to fetch it from Google, under Google’s terms.

Listen reads your PDFs on your device too. When a page is a scan, its words are recognised on your device by Apple’s Vision framework. When Listen reaches a picture or a table, it reads the description the PDF itself gives; if there is none, on iOS 27 with Apple Intelligence, Apple’s on-device model looks at the picture and describes it. Those descriptions are kept with the book on your device, and none of this leaves it. On Android, scanned pages are read by ML Kit’s text recognition, which is part of the app, and on a phone or tablet with Gemini Nano, Android’s on-device model describes the pictures; none of that leaves your device either.

The Owl has two other settings, and both send that text off your device: your own Ollama server, or an AI provider you supply an API key for. Both are listed above. Athene names which one is answering on the line above every reply, and asks you to confirm before the first time it sends anything to either. On Android, every answer from the Owl has Report this answer: it opens an email to the developer with your question and the answer in it, which you can change before sending, or not send at all.

Local network

iOS asks for permission before an app can talk to devices on your local network. Athene asks for it because your calibre server, your KOReader sync server, the WebDAV server you use with Zotero, an OPDS catalog or your Ollama server is usually on your local network, and because From a Computer receives books from a computer on it. Athene uses that permission only to reach the addresses you typed in and to receive the books you send; it does not scan the network or discover other devices. On Android 17 and later, Android asks the same, as the Nearby devices permission, and Athene asks for it only when you open From a Computer, connect to a calibre server, test an Ollama server or add a catalog on your network. Earlier versions of Android don’t ask.

What Athene does not do

No Athene account, sign-in or profile of any kind. The only accounts are yours, on servers and services you choose: a calibre server, an OPDS catalog, a KOReader sync server or your Zotero library.
No analytics, telemetry, usage measurement or crash reporting.
No advertising, no advertising identifier (IDFA), no tracking across apps or websites, and nothing shared with data brokers.
No third-party SDKs collecting anything.
No sale or sharing of personal information. Athene has none to sell.

Reports you choose to send

Athene never reports anything by itself. On Android, Settings › About › Share diagnostics lets you send a short technical log through the share sheet: Athene’s version, the Android version, the device’s make and model, when Athene last stopped and the reason Android gave (a crash, low memory and so on), and counts of internal problems. It holds no book titles, file names, notes or server addresses, and it goes only where you send it. If Android is set to share usage and diagnostics with Google, Google may report crashes to the developer as anonymous totals in the Play Console. Whatever you email the developer is used only to look into the problem, and is deleted if you ask at athene@theadipost.com.

Children

Athene is made for a general audience and is not directed at children under 13. It collects no personal information from anyone, including children. Because nothing is collected, there is nothing to request the deletion of.

Your rights

Privacy laws including the GDPR and the CCPA give you rights of access, correction, deletion and portability over personal data a company holds about you. Athene holds none: the developer has no database, no logs and no record that you exist, apart from any email you choose to send. Data on your own device is yours; you can inspect, export or erase it by using the app, or remove all of it at once by deleting the app. A copy in your iCloud is yours in the same way, and deleted as described under iCloud Sync.

This website

This site is a set of static pages. It sets no cookies, runs no analytics and loads nothing from anyone else’s servers. The host processes standard server request information as part of delivering the page.

Changes

If this policy changes, the revised version is posted here with a new effective date. Material changes to how Athene handles information will also be described in the App Store or Google Play release notes for the version that introduces them.

Contact

athene@theadipost.com